SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce6a3a0efd949714dd6822ff21f6a061e9644b57c3b15dcb4b2344adc91cea97' 
  AND token = 'C5CDgqL2/18VBnyCgqDOLBGopXBmz8jSov9mqaxibGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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