SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32621ae48aa01ab3bfedb8713ae753999d46712183b28918b1322b704228e501' 
  AND token = 'aIHWQkBEWiYbU8kYfqO1bVGIF1VdlEqSvibq9UbtUyE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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