SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72c4e750b1c79ec3d5cc21487aeacc096d88662772998d10637a3d88ee3709f7' 
  AND token = 'Wqd25i9x061xlhNQehv77KJjA2hPRRyU0KeSULQUvFQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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