SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52df6e00b97d1793772cafae433962e8aa5fa7e01671219c78bc8c83b5e083a1' 
  AND token = 'WSueZIdOJwuwZcqKpFsiqNkhg/zN8wgUNOnDvpoYC6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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