SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '959b2be94133ad36fbe3658cb336e322a2088cdcecc0f66b7bfc34c37bef8ab8' 
  AND token = 'kpFtRG/EiTKHpzMuSPxOEOhY3f9s39c7TkYmUEsei1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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