SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '784634b819b71e9fb300d5cb3a179a818eb0a574771444f7dda861b2e2c7c594' 
  AND token = 'yb1QxKQjNDPMZ5fM/+88HiEAspO2i+wFhFviCp281d0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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