SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83fcbf4f6bf50c74f4677db9c03fa0c2c0da3c908394bc87fcf708144bdc0742' 
  AND token = 'GlwTmAZ2E3ezAV2jsjpXNrL02vgR3R8nzjgzFz0dUxQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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