SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a5f6fb860cc89383c9c495e57b45160deed99086f1035105e0be732bb36eb7d' 
  AND token = '11eFwnwAlkV/pu1lZvPT82VgoOTzmKNbG9dTGK37zlo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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