SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a20060aa15d291edc2de823eaae2961d8e75abb50497c593c171c134b2fee1a' 
  AND token = 'OSPNHarC+g66lwZHrEA1eKYa/J55gsdMK9H9x80htIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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