SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff11ed15b5ce1a3072b7136cd46c1e4736a2c3138275fcf748449a50e9d4e243' 
  AND token = 'e5SgPmhnqQ+MIB7w5mlRjvequsLbpocjn86WVeF8OFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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