SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37e49534d6db5d7430bf1c8b7ebfad8f4c421de3db74267ddc66c8f0a03d159f' 
  AND token = 'U72ZsZ/JIuZdHZ/zGXYbY9kvmwcDwkJ6oznQc0ZBwJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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