SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '269fadeb3ce00e0d4c3c812baee05bdd1f46918be06d0a6bf4c7f13735b24325' 
  AND token = 'WswcfisZ5Q2vY7OZf9G3HwfWWIvvGtCZULXkhtss4Bw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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