SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4feb4d379a2be9f6d7c5aab9690276a0a3af8eff832b43c702db7c1535987c0a' 
  AND token = '/L5wK8GOHDj7RMw1gYxALiXg3PoVS6wpsxChbiyAwtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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