SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cb633975559bb5513caaf71b359f6e9a5da3d568204c82479c4deda37478d19' 
  AND token = '5hXM5QwWErRR6OvD/i9C0W1Odu1NXr1FWvq3Tmf5BnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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