SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b4d45485fd7b0061244c627732efda44f042bb24b5cfc0013a0d421e4e46d075' 
  AND token = 'CoOMpejd6URqzK+Jf5+iSmkDSLpI0gRvggpCoxQb90U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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