SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4ec6e1c90248ebf02d2a331481d05b99b5f9c2aa2b2a40cb7d04f257826c9011' 
  AND token = 'w0yzwVvJvcqnsy8nKQ3hX0aY6vMdG8hPZ+SMHBCsDWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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