SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b7aa4870a9facbf58fdae5a5a362c6162c600ea21cf2a5c9e7222300da89013' 
  AND token = '8ZvU/X+Ed3k5dFERFNCW8LR4MRjD9PrXD4AP7soxGTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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