SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d580e1fb79f85a8c9d9534e6320175058389e88f945d7f69624ce696a00ee8c' 
  AND token = 'i+2sGCXpeaGWgeXlHMTYtTjtgRspLrgHYYXV+T3oFzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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