SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9093f0db7aad7564092acf36e7aa19f0c8b3b13b87f059b0d20251077245f76' 
  AND token = 'lTGzjMCYG1fI5PXhSLAW1xvFvETGb2bLh7MbapORIV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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