SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e63285177516ecb637f4ece8c8f3391b84896046671ef3c45defbdf179b9cfd' 
  AND token = 'CUA1PBTLIRNUEU6+qxqwndZNWfySHVbvzcKdAVXb/DM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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