SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd886e45651dec5c1af3eb07240239fc00505497bfc3ea49d2eefa850435a9fe' 
  AND token = 'CXoskiVu0Wens0h0cG4nMgzHca/ZYZUpPCSNDhv0GGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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