SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1744c73a7454a8ca71be4e4d24da6e1dc13065a050810f96f21b3062a923e1af' 
  AND token = 'sMk28tLrESWp+AATGmMBtvCgWfUhKVHxsM+P5oEe85w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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