SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd32c54c74bbeb1852509edc33bd88e7b622adaf4f934aac6b7a64a1b442eae1c' 
  AND token = 'ArtPW1ObkkNQTgpHMpnJ8knfl4YGW7wE/bOsymJo2Wk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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