SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be7c1f03e2b87bcf13cc81f8586f5ab00b7d06ea36ccf6da0a2bde09fb173589' 
  AND token = 'FSkMfpCsHOBd0Su6PCO74A6YqByEV8DxamUoXykjIQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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