SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '845d8c21c761ea18d5fe885a65b86f9a9890c61233d71f8beb2394603bad2970' 
  AND token = 'gyltQXsNJvNdvuK7hzpsxFJ89W5wbHwqTq1P3tmTx9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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