SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e5fda89c5cb2cec34e22a64fde930b27d73a8b4601e9e4022ad68b5a1e61130' 
  AND token = 'ykdhYfu6OGq8ToD+H11bnA2eBSxiZNdBMe0FkwZGn4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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