SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cdf02d0bd4227e817680cef47637786c7e116cff55fb9870048ba3f743a7cb8' 
  AND token = 'TFBl9U7gNbbe7TLovYVE+NfGq1nsRhhyaMDB4Da7pcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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