SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b707b13d0f5579569fb599f5916cd29ded9c1923e421d0b8c55ae3cc83d73a6' 
  AND token = 'PUaRu32lTJqjU8O0AGNuEUBhZ9lNWotU+t7petIfjTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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