SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7dbaa41b58cb119747cfcb233a6acb98953245f96b708610739cfa4abb708bd0' 
  AND token = 'rrVtPjLZg9kJ0M7Ovl2v/jSVvZqQ3jr3LDE2GawO1YQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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