SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca6a97fe805687bb2c39231fb19131b427d8e4e162258846424bdae0aef95b7d' 
  AND token = 'denU3hpXWo8INX2Lgnj7o+rcQsjJ3LQLQsL5Z8ld5sE=' 
  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"
    }
  }
}