SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acbace151fcee4f7f3558be0fee9df68f5f7ce97316db45d92c0c89778198457' 
  AND token = 'hJgvKVf+HDy1Ld/hRFNDQCGtRnUaze48Ag7uJV45X7I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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