SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8c28da3b4956565116cf72a3a1cc8dc7f3086c43560df61522583f8edacebc3' 
  AND token = 'Pue63ojo3s5Bxo5ZbVBMqjIfFb27UcWRbSKzR/gu+bo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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