SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93618df0c763e808192f4933ed2deb1635f8000611e9dd9266c5ea430494fbdd' 
  AND token = 'pnz8+5T8gTfxje/2nBq45bAEtMqJ7LRy9r6+v0n+SyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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