SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e2963e7cb25e63a38806eff9d60bcb026bfb446afb3b82871b0de32bb6a3a26' 
  AND token = 'B54kvgVhlVK26qhlBaGOCL2VrC/r1HQW3MfjIFAAWzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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