SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b424e8e7b93fdc66104acb4e51c60e37f68219a2e3e3af879ddd33198772afa5' 
  AND token = 'J7TWdjMgsZpvavv/0UXSWY/EnjkshwxRiBU27kf0QTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00065

JSON explain

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