SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce27fa6c3deb43ad8eb5625445b21510cd4ce4c05ac3b8f6d682b60aac305e89' 
  AND token = 'PheONhwOiQ5chhr0vJTLYCSYdrSNpMuCvRwKmwnTYX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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