SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '81bcd028fdf3061b9f64f1849a97b3d3728e51189b568bbb3a846b2cfc4a0043' 
  AND token = '8hwl2z3fZNwN8CmE4v73Fjf30B+XRegjPV8NnWfLMis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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