SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b7444d92299d989e51c72f5dc2d087999d69ecc99db3d98ce4db30292e5401e' 
  AND token = 'PHQftDs0PT64YkfYVXTgbNAdCMJKqX+ouC/Vy/ANT0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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