SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c61059a1c5c555fff33f327018f9533cf9749b45adb0347331920001329b0a4' 
  AND token = 'NXs9CIL5GuV3wI1Dwr9FXJBQXP5O31Ar+pYT2YQMlAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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