SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5560d1f1ed6fd18fbb610a457201c0beeb8d94a34df4af3825fa9ef3f5f4ee1' 
  AND token = 'hs9RNnKxIoXLUZUb7GRAnJtUw/P2+S/1O/UgvuT3dew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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