SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0931c9135952072f0be5ee7619187acb661057a4bcdb2b82475901d4365ef19b' 
  AND token = 'QqVmDh2jfTo5+iYTWv46HQALeSsCGO+8BOXMpQCq3CY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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