SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a64bd277efe7f3a0833f785ea06c9665948726795fd9e906ebf2ad5548940d2' 
  AND token = 'wzluKsJksiQ22kmnndPc++rg9FGhygojtrndBwD1N2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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