SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1b275f18bd71a0e5e1a9e7cd89e799ba1400230cc771219914b4c1810630c0c' 
  AND token = '+yjMcSJuMI4KCuntkgDKqWHjFx4+qKKUhloOrJ7yQ/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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