SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd241b5cce75166a15a6824cfc56dda1a96c9f9d81d20e675925246678e54192' 
  AND token = 'jW6rhGSOj0x/VftsVZcSnjA6VqFxNO1vzcpgYohTiU8=' 
  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"
    }
  }
}