SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fae61ed64786ff6ac317be5bde5543855eaf37f887577209afeff0dcd2ab0fd5' 
  AND token = 'UF1/TzJ6gppwMq+J5GsIpZuZKPvgFIArZpNAPua2eSs=' 
  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"
    }
  }
}