SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6205436611485a6fed5737aac826214e581e0a65b35fe1456a2dff949f321c24' 
  AND token = 'iI8tSxHWesMwccIjz0zOjEKZtnwBpcKEBI36He7v9UI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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