SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98ca4d8e628666ba5618102fd84c20929618c746c3c9852459d385d2a3316c3b' 
  AND token = 'Uhl5nado/pidb87MHd+G635YX8il+RQiCP2cnzp4rGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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