SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed2df5c7c9117a76d0a587b3ac1d863a308e270c4f8d3f85f16634ed27a0d505' 
  AND token = 'wHu+B9FQO1DzGFa/ls4Pj/kPCyhSGaJPPmm+dkluXjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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