SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '163dc27a1cf275fcb710f9ab9f61f81cb176a441deb4a15550b47b02bd535ba6' 
  AND token = 'qYFIejhDQtK9qoD5WCDa3ewcJSp8RbdP2cXOE6aqz7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}