SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9a6e6d6f9b98edc4fe7ad61182d1add23a61ed859a1ff72a4d75c098d2778757' 
  AND token = 'K3hLA32mjY8GQqcohxVjiirLPJQScWm7ARo8NvP3zPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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