SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50406718778ccaf5466a55204d6bc9671b42268bcafb0373cb9b99fec26bd5a7' 
  AND token = 'sdiaoxXgrA4oEwlrMJm51unvcTuUBPXPVFKhVB1NJZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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