SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2d8be9ad8c76f6a637b655673de4bf45ab3952a44481a4680b363f026a532e8' 
  AND token = 'M8WV7KfPZ1hbEAGX6gwlJn29pkt6xkJOYqLJBkeyi/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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