SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c38179f0690c568be26d29bb45bd1d48e770c0a8f9aed7132cbea197e6c0c97' 
  AND token = 'goEyPjwQ15IlBkb+jjMZzMtgk5pXglRmmTpB183vgCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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