SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bf7e257aaf410e9c415aca08e8f94d0cdc176321f77dab56a345f2df9288a9a' 
  AND token = 's6pFpmmQHaLDNmHnkTO0sWSWuty3ZrmLuWaaCkjdemc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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