SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfe67a467aba049e53869ff9400c5888ec67adf5c37ee7599ebd01ab354e58cb' 
  AND token = 'WPWLkhAPflF4qEto/oIOoreYPiygjEWWPaZ5dKkRGgc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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