SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aed679a1fe14f60db474207696f07819c5c7c33c8ee0dbf884859d881c938006' 
  AND token = 'bjZBYlkplzYYTFw1PJIRSflDuWTWjNkOxC1sdSo8QpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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