SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9bd0b0fe8ebf50fce9c02104abcb1a45f64e67773db6b1ebfab8d6f69736a70' 
  AND token = 'iW2hUt0V2xbcSzbqEDjuMrqWiTRzWtJjxaZIbaEuadw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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