SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40c325b851b8664f74763953ef47f07826ee77148d0ce580e24be96f168b974e' 
  AND token = '/VkiT6IKrXrkzaOcqK1urxlJ85h6rrVITEutBImSsjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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