SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1abd9dc99f1f38c033a7f0714878929486e25fcfe5a25df6d7e59ae0336e700' 
  AND token = 'pY3LGjb4zWm+t5QqvOLqGSJkspjJic5elkJzuWKU2gY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}