SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a1308f06480962ec7f2fe959f183a0fee5f1e93a6e56b8a7157bba03d9a1ac6' 
  AND token = 'aqSYT4OtGrm9dRvgeeiuGSaET2Il3FtfKBBnVcyS9lQ=' 
  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"
    }
  }
}