SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '169f4e9fe281204da9ad05dbb5a87cf0ec35f0288057dac9cd31e3070a378309' 
  AND token = 'qeEdn3UM0d+TSUg7Otl5H3M2S4++tP5cO2p4/Nnyn2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}