SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ea103db3604c409dbcaa3782ea538e5eb134be2376422b30172fd991e3783ad' 
  AND token = 'XFPrnlq/6esI7YzKgV7Rm36E+/n6fYjClBUsca3ct+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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