SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '5e859e1a8371fcf38bc75dd6f8a930ec5b285daa09a1be5716a04179bde7b467' 
  AND token = 'yG2BIj1g6oxhLN2Bw9/b/t+MADjSB4Y7TnKMKnYkilY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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