SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e757a6031453754cd9630eb4d61d29baab3036403cbef887a27c6eb151761e58' 
  AND token = '33xV9QOWyV2LhuVCUPjc84NfbBdfH4cPpCAlweEHKsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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