SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0fe271c0a56820bce2c6b3991652b1c0c88ab2f50686c8019f014008c9ddae1' 
  AND token = 'YZk7xad0d2NYUfb4aDzB34hMMmlWtxgmdXJCF15HrnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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