SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '205372d6c41fa25dc8aab82c64f4256624ddf23fce8aff0ec5b530fb02010d31' 
  AND token = 'FyGuo+NAy6jpuTP4EMvNjHovoqQzac1C4IjvUa9vMt8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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