SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '357d11941cf2f9a41cb3e7bc08ae9ccb3970716eddc209369f55ea526574af89' 
  AND token = 'ELb1PskJIptcOhnjE6pzQhH/hqspfTpyrajamddYYUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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