SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48532cedd8ac3a5211d6c96074624e1b7233a169ace4131bb74a7be0a500f61c' 
  AND token = 'bE9jn2EFo7VIqWIghYv+Q015v3CKP+/jZuDVAGsRjTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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