SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1a997fc805f933f8e575e5e4ffbb4d9e7a1aba2931627559580459e27a5cf4c' 
  AND token = 'z31+oYPPmk9OAvaGz3/D45RFd63+dls80MBzk/IVNBk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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