SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96dbcee904fe86da111f0db7cb8b69229a0745a344f21dc2074f6770a25630f6' 
  AND token = 'B1KZWa3OjeV3uNr0Xl+BJXwbwMD9oSST+0vbElaTjCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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