SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf888ce6836cd28eb4b12c617afda2ba388b41bf2c3d242a3ff92eda3627f5fe' 
  AND token = 'qefsVN68PCCghVUNntBcb2YVn5wrMjwFH+lLPGIX3Xs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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