SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a99e11525a9345fe95d64a71f76bd9586133f781c86d5a1cf11612019dfa327' 
  AND token = 'WUOSPRjVry205xSDvyL4baxQ1JBamuJYVSLJlYCbsro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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