SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00d26eb37a19e8cd58530921dfdd7950bd6e1d81293c70a5abdb470f2324b63d' 
  AND token = 'KVQIwM/NON878MEjCUX2Dj2WtIOKDJNtHo/8bNiYEAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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