SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '537caab3206949fdefecad8bb164027eb6be04cfe5c74a910fcac97b7fa3ff9e' 
  AND token = 'nOgYAyMBRu9Y2OQqpigsNIzZfSKrc/I8Yv5KTzfCYQE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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