SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '8831e1f445b8326f33369fea33b4b31dab6acbebc68a49f6911634640d99bbf8' 
  AND token = 'RhWH1fgSBRZ1DGNlwUr/WgI1/xh0qpXbayxsgjUNP5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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