SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3775cb4a80225b3b9a1c510e3f79d830106ceab00f40c27b45f23c109f1d77e' 
  AND token = 'yd2OtQYw/knKJyS4TGtv1+p2ITrX21b8JnpGCvJKZhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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