SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7efbcd58cdf1ae2d87ccc455003345a0129f3fd3292c71e16beabdf30f779b39' 
  AND token = 'DC6KaagoPJOAXSHnR/Z+uIO9GXWXjB1wK86ZCz/EXCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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