SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb04ac65e1efe013258cbe38cf66cd2b530780e2473e63e2f1aecf2add1077d6' 
  AND token = 'ylv5xTj/5MnBVeJpDPx8lv3pTwPUirCICWDTyjNGe4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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