SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b2b7477f6680afb378ed216d85c5bbf96028c37f80bd9e80d4a42be244640b0' 
  AND token = '5Et2G5wJQfWpcxcEHVf+xlJ1ooUDQS0U74tup2EzuTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}