SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '105aa4e3c054144765321c5471dcd11784f2725ace198b52514a019a8230459c' 
  AND token = 'wvzkmKNzxtI2+mBB9DUPVPTBUaiQNQAdb/Ex65GRwnc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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