SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '153fc40ecf48c18a74af517fbcb3eccd24cac941b6f1f006947257b490a5bee2' 
  AND token = 'Peot9uPU2NYHu6hoMhzT74f8ttmddevHTSVw/WdfpTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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