SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96463cf44fe8435c40d5cfe8683b0bf69dd2443fca207a86fb7e4a0062a707b1' 
  AND token = 'DQwR2sCstt2QmRauFfDr0xQT1vhyeSvAYpHadJqNt2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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