SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f67a5a56ecb49567423fc88a7cfabe20f35777ccfa66f3f691c118ab86b9441' 
  AND token = 'OWMyK2x/q4br8D2/W4q1IGQ/lNlmQYND/blTk9G9SUY=' 
  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"
    }
  }
}