SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '679fbc56ad93c534f9e2ce52c42182bcad54db9980f5fb78d3d0a1a2aa3a3c24' 
  AND token = 'HTEqG4K/i7Bc/FYDnqC4CgWxOE1LA1Nm8vgPVLqBIvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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