SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36bffa9919a628a4baf551e5f3a64852028649f0fe5243266fdcf35e38c4ebb1' 
  AND token = 'i+HGyxMgy+pOmbwF8zIc3fGgh/1BHL93NKYjmDYwN8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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