SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b7e72b4d399dec0ba0bed18599c889054cb9ca640781dba1256fb92802e0926' 
  AND token = 'R2X5wQqDDHDoW0Okw2Sm4JFcPKp82Wt9DfZolPyVsso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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