SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcfd4eecec408589ba077c5d8783c5fea4b3756ab4620a2b7e7c904a7832c813' 
  AND token = 'zKvk9M9rztgCvUvfW5X8Mc2jq1YRb6Mhl6DyMRd/qTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}