SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0f6980428098b36595b2c7d948f51615396dccfc4f47a5ad584ea019ef220a02' 
  AND token = 'eNCgfY/roHBr88Yeb7JkVKztqQUQE92TvSW91JtGVcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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