SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb57ac05d5fb6998d1f418e9eb033af0da5abb207d8f1f1a4c563b5d0a38af69' 
  AND token = 'x8eNIEyvu/JR8PHQRybpHVF0RhpuQRJe8ngCLtYocgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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