SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42506eb6ecf89fd59172f7dee44bfb6b390f8e3a22830a27cde81d5a9e8e2608' 
  AND token = 'bFyJ+TPH6jnNYvinG7FQIZmaKF6+92zjbz1RDYtQ8wc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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