SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '425842756d9bc9f521967730968b2abbfc694263d772b4110a138923deac6601' 
  AND token = 'n7TU+1vKZn3umux8vIMB+fVspYJSLJAUyCSgHVqHVBk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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