SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7e46a4d9f7a5e9d19f29d57eb6e6d83d34f40141c0408ae79a0a6c0ef36d62e' 
  AND token = 'JUIUwywWuYxUmnABpdAg17Jnuv+02HujyX8SqK/pT7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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