SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6c370317c835d88f9f2144d1d2775b8c154fb3d44ecf564177f59f3025d1f459' 
  AND token = 'SznrZLYpoRl/nWMrqeBa4sf0GjesW/rPjHoifuofaE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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