SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4ac6b1365692c09f27525ae859b224910e7e109b7b99ec7524d06a6002cf833' 
  AND token = 'CX6VfJSUfVWZkrAe1OrwqCbQ6+4FzfRMw9gscorG0u4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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