SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e90ce312918ffe4933336d0cbb583a61c29b69ab59dc73d1b870bfa1f7411d3f' 
  AND token = 'xF7gfFmvbOUU5ZnTNeKgsvp23hXFC35RtScnSjJPrck=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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