SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ae76953f6ccbdf9fb086e1ded52f846f6004865634d4ea898027db65256d8df' 
  AND token = 's7tmwZTzBIXECSsfQAf/74goGkGsiFFOx9td/Qgqzoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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