SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '696a43244451c2c8e6a4c6b97aebda26fb256af34775c3dd23f08fd923e8bf75' 
  AND token = '8SBDMJxkK8yBlLOvErWOSR/vamcBKYTHQ1tpmqxdZZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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