SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a666f0bea22307be9180628ca9d0e27f39059579fa067006ef43e4710216fb1' 
  AND token = 'vgWKbcJUbHwLt9s9nrcd+R9u9W2CAGFr4t4HmqmJAkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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