SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89f6073031706cf15fe324a0ce084bb9a9a55de038177f948b287c3afe34e748' 
  AND token = 'Et3qsvfhIjxhTSE/hcm5Fg7Ru17S/HfCHlGP+emSjTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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