SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd494034ad4303f0b27eb995be5116cdaefeef3761357f124747ab9db41f97868' 
  AND token = '/Xtll4G/X3FP+8vJopxhU3Puq2pD5pr0+d2RUsp6DsY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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