SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d6d0726cdfb6bc991b630e25976851227abf6fb79b26cfd8152e47d2f915492' 
  AND token = 'cwiVL6JnshcNf92lP3jO28YA8/xm+G5am6DfT61ysTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00091

JSON explain

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