SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c1dfca0432610ddb3ae2a5500d5139be92b655df6788c4f13a7788f1d72a52e' 
  AND token = 'houWEq30ird0LtZdOmwV2+zjuZdbp6P5Ts/vpQoGOJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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