SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5c893880f9d91274d77b9d155f68a898e148d73d4c0497b32ce629867d01f3b' 
  AND token = 'LgIvOlVJuOU0L4vhh/DeF0G6VMtwwN4rLVcFDXj0vkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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