SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08cf2f5a301e0b8091f0a04413cfd404eaf6696fe9e4ab455f53df99857bbc82' 
  AND token = 'gAioa6SNUBEAlLynFGcCqnrvlhDmMbu2Qw6VXN6BU98=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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