SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '699f1f345c0ff8d3a14eb697470d31b6129792a850e5e2f9ccc2efa8b6293c0f' 
  AND token = 'Mx6+gPSNhqYaV9G6Df/vuhF2LYysM36NF4VJfrSjaQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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