SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20032dea3e3eba2334aba2993c61811f81ecb9422ba5816a8ed08cdc1d57e75e' 
  AND token = 'xqZoKKQP0ii4RIPejpemr4KMcoxLRChonsTZCtlXtUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}