SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35f080c13b3eb5ec17fd98541ce22113b99253c4bbc96102e2b889b6f1ccdcd9' 
  AND token = 'pCJdrsBcghyWVz/EczvSX6qYurL9VXis9vKmftvDBQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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