SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a5ded9f51f849b088e11b15d4850882782e3cb41ffc19e2c260fa62fa72a9e7' 
  AND token = 'wf+NrmcGYOnlZxbZPQY3Eqlvy7ZjTcDNxH8xM1X3bIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}