SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d6e56941d550ea54097c5da5bcdc1d909014db9c5e1b9636dba8feb2fc7cd97' 
  AND token = '3TeM/47HRSZflFPA/ImZeFNbjVCBjtDdgR+6AM0sWYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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