SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b44975512a83ce14d7ca33ba25bcc5b275791d26fd242de5566444a5055186cd' 
  AND token = 'gUPVMx39ZpVPUmGFjiClyh+cQNZVSv0wLI9RaCERKnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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