SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8236dda1e14fd2a606a1fc14650c86f2da43b2dda6962e961e059c926c398aec' 
  AND token = 'oVYCMgvl1edOGxnlsIqB01LcwuxU8TWOH/7CVzLI6VM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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