SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1cfd358e505bd40fe3d478d51e25fc6e2b35cfc7568af18d5e529cce8883d99' 
  AND token = 'OOUjE8q+vIBOzAx+sxo1t1hZyjAdKCiM5vTimD3KoKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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