SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b58667022e7261eb725ade57a68e9a806262a0a91302224c4154018fa51b42c' 
  AND token = 'fyfILLGRYIKNDAz7sRNAZYVSQYM4KcrqwSHFw7mYAOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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