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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9560dda00e2cd47b91fb8219e041ce1b8df76de5415c17cef00adb0f15e5e01f' 
  AND token = '9L6052GAKOuIh08ky6O2+/fzmx2iE3LIIQDGAT2waWs=' 
  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"
    }
  }
}