SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37ade2058aaad80c2470171cb69602cd3dcdeca2f019080d9e73b27eee0efefb' 
  AND token = 'Ol3zI1Luhcy48rqwOt89kA9jwAsZD5W0dA6NQsjpUhM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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